1. Field of the Invention
This invention relates to a method of forming a spin on glass film of a semiconductor device.
2. Brief Description of Prior Arts
Generally, a spin on glass film (below, called as xe2x80x9cSOGxe2x80x9d film) is widely used as a planarizing film of metal layers in semiconductor device and formed through a coating process and a curing process. In method of curing the SOG film, there are methods using a furnace and an electron beam.
In the method of curing the SOG film using an electron beam, electron is accelerated by high energy and then implanted into the SOG film. Thus, the SOG film is cured by a collision energy and heat generated by collision between electrons and SOG atoms. Therefore, as compared with the method using the furnace, moisture contained in the SOG film is removed completely and the SOG film has a dense structure. However, a disadvantage of the curing process using an electron beam is that the characteristic of device may be unstable by a shift of threshold voltage.
Therefore, the object of this invention is to provide a method of forming a SOG film which can prevent a shift of the threshold voltage of a device.
To achieve this object, a coated spin on glass is cured by an electron beam with a low energy, the energy of electron beam is between 5 and 7 kV. Also, a does of said electron is 3000 uC/cm2 or more.